On a surface view, there is little difference between direction and supervision. Both are concerned with initiating action. Both involve issuance of orders, instructions, etc. to subordinates. Both seek to motivate the subordinate staff and provide leadership so that the pre-determined goals are effectively accomplished. Also, both consist of maintaining discipline among subordinates.
However, despite similarly of functions between direction and supervision, only the lowest level managers are designated as supervisors. One reason for this is the while all other levels of management have subordinates who are managers themselves, the supervisory staff deals with workers who are engaged in basic operations. The only other reason may be that while supervision is one of the many functions performed by managers at other levels, for the supervisory staff is the primary function.
Generally, supervisors pe1form all the functions of management, through in a limited way, and in a limited area of operations. In an output-line organization, they are responsible not only for supervising their subordinates but also for planning, organizing, staffing and decision-making. Even in the case of a functional organization, where planning, organizing, staffing and decision-making are under the charge of specialists, supervisors, ensure that performance at the level of workers is exactly as per the plans and policies formulated at the higher levels. In a case where performance deviates from a plan, supervisors, being men on the spot, promptly initiate and complete the necessary corrective action without much loss of time.